Not sure what those instruments since they're not named are but each type from what I experience seem to be different "instruments" and each different sound bit is a different tone from that instrument. But it most types seem to be reserved for generic GBA bleeps and bloops.
As I dont' know what those instruments are, I do know Type 9 is guitar and type 128 is your percussion.
(Btw, I found teh WAHOOOOO Type 8 @0x11813c)